<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="my.css">
</head>
<body>
    <h2>外部样式1</h2>
    <h2>外部样式2</h2>
    <h2>外部样式3</h2>
    <h2>外部样式4</h2>
</body>
</html>
